ceph/doc/radosgw/config.rst

===========================
 Configuring RADOS Gateway
===========================

Before you can start RADOS Gateway, you must modify your ``ceph.conf`` file
to include a section for RADOS Gateway You must also create an ``rgw.conf`` 
file in the ``/etc/apache2/sites-enabled`` directory. The ``rgw.conf`` 
file configures Apache to interact with FastCGI.


Add a RADOS GW Configuration to ``ceph.conf``
=============================================

Add the RADOS Gateway configuration to your ``ceph.conf`` file.  The RADOS
Gateway configuration requires you to specify the host name where you installed
RADOS Gateway, a keyring (for use with cephx), the socket path and a log file. 
For example::  

	[client.radosgw.gateway]
		host = {host-name}
		keyring = /etc/ceph/keyring.radosgw.gateway
		rgw socket path = /tmp/radosgw.sock
		log file = /var/log/ceph/radosgw.log


Deploy ``ceph.conf``
====================

If you deploy Ceph with ``mkcephfs``, manually redeploy ``ceph.conf`` to the 
hosts in your cluster. For example:: 

	cd /etc/ceph
	ssh {host-name} sudo /etc/ceph/ceph.conf < ceph.conf


Create Data Directory
=====================

The ``mkcephfs`` deployment script may not create the default RGW data
directory.  Create data directories for each instance of a ``radosgw`` daemon (if
you haven't done so already). The ``host``  variables in the ``ceph.conf`` file
determine which host runs each instance of a ``radosgw`` daemon. The typical form
specifes the daemon ``radosgw``, the cluster name and the daemon ID. ::

	sudo mkdir -p /var/lib/ceph/radosgw/{$cluster}-{$id}

Using the exemplary ``ceph.conf`` settings above, you would execute the following::

	sudo mkdir -p /var/lib/ceph/radosgw/ceph-radosgw.gateway


Create ``rgw.conf``
===================

Create an ``rgw.conf`` file on the host where you installed RADOS Gateway
under the ``/etc/apache2/sites-available`` directory.

We recommend deploying FastCGI as an external server, because allowing
Apache to manage FastCGI sometimes introduces high latency. To manage FastCGI 
as an external server, use the ``FastCgiExternalServer`` directive. 
See `FastCgiExternalServer`_ for details on this directive. 
See `Module mod_fastcgi`_ for general details. :: 

	FastCgiExternalServer /var/www/s3gw.fcgi -socket /tmp/radosgw.sock

.. _Module mod_fastcgi: http://www.fastcgi.com/drupal/node/25
.. _FastCgiExternalServer: http://www.fastcgi.com/drupal/node/25#FastCgiExternalServer

Once you have configured FastCGI as an external server, you must 
create the virtual host configuration within your ``rgw.conf`` file. See 
`Apache Virtual Host documentation`_ for details on ``<VirtualHost>`` format 
and settings. Replace the values in brackets. ::

	<VirtualHost *:80>
		ServerName {fqdn}
		ServerAdmin {email.address}
		DocumentRoot /var/www
	</VirtualHost>

.. _Apache Virtual Host documentation: http://httpd.apache.org/docs/2.2/vhosts/

RADOS Gateway requires a rewrite rule for the Amazon S3-compatible interface. 
It's required for passing in the ``HTTP_AUTHORIZATION env`` for S3, which is 
filtered out by Apache. The rewrite rule is not necessary for the OpenStack 
Swift-compatible interface. Turn on the rewrite engine and add the following
rewrite rule to your Virtual Host configuration. :: 

	RewriteEngine On
	RewriteRule ^/([a-zA-Z0-9-_.]*)([/]?.*) /s3gw.fcgi?page=$1&params=$2&%{QUERY_STRING} [E=HTTP_AUTHORIZATION:%{HTTP:Authorization},L]
	
Since the ``<VirtualHost>`` is running ``mod_fastcgi.c``, you must include a
section in your ``<VirtualHost>`` configuration for the ``mod_fastcgi.c`` module. 

::

	<VirtualHost *:80>
		...
		<IfModule mod_fastcgi.c>
			<Directory /var/www>
				Options +ExecCGI
				AllowOverride All
				SetHandler fastcgi-script
				Order allow,deny
				Allow from all
				AuthBasicAuthoritative Off
			</Directory>
		</IfModule>
		...
	</VirtualHost>
	
See `<IfModule> Directive`_ for additional details. 

.. _<IfModule> Directive: http://httpd.apache.org/docs/2.2/mod/core.html#ifmodule
	
Finally, you should configure Apache to allow encoded slashes, provide paths for
log files and to trun off server signatures. :: 	

	<VirtualHost *:80>	
	...	
		AllowEncodedSlashes On
		ErrorLog /var/log/apache2/error.log
		CustomLog /var/log/apache2/access.log combined
		ServerSignature Off
	</VirtualHost>
	

Enable the RADOS Gateway Configuration
======================================

Enable the site for ``rgw.conf``. :: 

	sudo a2ensite rgw.conf

Disable the default site. :: 

	sudo a2dissite default
	

Add a RADOS GW Script
=====================

Add a ``s3gw.fcgi`` file (use the same name referenced in the first line 
of ``rgw.conf``) to ``/var/www``. The contents of the file should include:: 

	#!/bin/sh
	exec /usr/bin/radosgw -c /etc/ceph/ceph.conf -n client.radosgw.gateway
	
Ensure that you apply execute permissions to ``s3gw.fcgi``. ::

	sudo chmod +x s3gw.fcgi


Generate a Keyring and Key for RADOS Gateway
============================================

You must create a keyring for the RADOS Gateway. For example:: 

	sudo ceph-authtool --create-keyring /etc/ceph/keyring.radosgw.gateway
	sudo chmod +r /etc/ceph/keyring.radosgw.gateway
	
Generate a key so that RADOS Gateway can identify a user name and authenticate 
the user with the cluster. Then, add capabilities to the key. For example:: 

	sudo ceph-authtool /etc/ceph/keyring.radosgw.gateway -n client.radosgw.gateway --gen-key
	sudo ceph-authtool -n client.radosgw.gateway --cap osd 'allow rwx' --cap mon 'allow r' /etc/ceph/keyring.radosgw.gateway
	

Add to Ceph Keyring Entries 
===========================

Once you have created a keyring and key for RADOS GW, add it as an entry in
the Ceph keyring. For example::

	ceph -k /etc/ceph/ceph.keyring auth add client.radosgw.gateway -i /etc/ceph/keyring.radosgw.gateway
	

Restart Services and Start the RADOS Gateway
============================================

To ensure that all components have reloaded their configurations, 
we recommend restarting your ``ceph`` and ``apaches`` services. Then, 
start up the ``radosgw`` service. For example:: 

	sudo service ceph restart
	sudo service apache2 restart
	sudo /etc/init.d/radosgw start


Create a RADOS Gateway User
===========================

To use the REST interfaces, first create an initial RADOS Gateway user. 
The RADOS Gateway user is not the same user as the ``client.rados.gateway``
user, which identifies the RADOS Gateway as a user of the RADOS cluster.
The RADOS Gateway user is a user of the RADOS Gateway. ::

	sudo radosgw-admin user create --uid="{username}" --display-name="{Display Name}"

For example:: 	
	
  radosgw-admin user create --uid=johndoe --display-name="John Doe" --email=john@example.com
  { "user_id": "johndoe",
    "rados_uid": 0,
    "display_name": "John Doe",
    "email": "john@example.com",
    "suspended": 0,
    "subusers": [],
    "keys": [
      { "user": "johndoe",
        "access_key": "QFAMEDSJP5DEKJO0DDXY",
        "secret_key": "iaSFLDVvDdQt6lkNzHyW4fPLZugBAI1g17LO0+87"}],
    "swift_keys": []}

Creating a user also creates an ``access_key`` and
``secret_key`` entry for use with any S3 API-compatible client.	
For details on RADOS Gateway administration, see `radosgw-admin`_. 

.. _radosgw-admin: ../../man/8/radosgw-admin/ 

.. important:: Check the key output. Sometimes ``radosgw-admin``
   generates a key with an escape (``\``) character, and some clients
   do not know how to handle escape characters. Remedies include 
   removing the escape character (``\``), encapsulating the string
   in quotes, or simply regenerating the key and ensuring that it 
   does not have an escape character.



Enabling Swift Access
=====================

Allowing access to the object store with Swift (OpenStack Object
Storage) compatible clients requires an additional step, the creation
of a subuser and a Swift access key.

::

  sudo radosgw-admin subuser create --uid=johndoe --subuser=johndoe:swift --access=full

.. code-block:: javascript

  { "user_id": "johndoe",
    "rados_uid": 0,
    "display_name": "John Doe",
    "email": "john@example.com",
    "suspended": 0,
    "subusers": [
      { "id": "johndoe:swift",
        "permissions": "full-control"}],
    "keys": [
      { "user": "johndoe",
        "access_key": "QFAMEDSJP5DEKJO0DDXY",
        "secret_key": "iaSFLDVvDdQt6lkNzHyW4fPLZugBAI1g17LO0+87"}],
    "swift_keys": []}

::

  sudo radosgw-admin key create --subuser=johndoe:swift --key-type=swift

.. code-block:: javascript

  { "user_id": "johndoe",
    "rados_uid": 0,
    "display_name": "John Doe",
    "email": "john@example.com",
    "suspended": 0,
    "subusers": [
       { "id": "johndoe:swift",
         "permissions": "full-control"}],
    "keys": [
      { "user": "johndoe",
        "access_key": "QFAMEDSJP5DEKJO0DDXY",
        "secret_key": "iaSFLDVvDdQt6lkNzHyW4fPLZugBAI1g17LO0+87"}],
    "swift_keys": [
      { "user": "johndoe:swift",
        "secret_key": "E9T2rUZNu2gxUjcwUBO8n\/Ev4KX6\/GprEuH4qhu1"}]}

This step enables you to use any Swift client to connect to and use RADOS
Gateway via the Swift-compatible API. As an example, you might use the ``swift``
command-line client utility that ships with the OpenStack Object Storage
packages.

::

  swift -V 1.0 -A http://radosgw.example.com/auth -U johndoe:swift -K E9T2rUZNu2gxUjcwUBO8n\/Ev4KX6\/GprEuH4qhu1 post test  
  swift -V 1.0 -A http://radosgw.example.com/auth -U johndoe:swift -K E9T2rUZNu2gxUjcwUBO8n\/Ev4KX6\/GprEuH4qhu1 upload test myfile

RGW's ``user:subuser`` tuple maps to the ``tenant:user`` tuple expected by Swift.

.. important:: RGW's Swift authentication service only supports
   built-in Swift authentication (``-V 1.0``) at this point. There is
   currently no way to make RGW authenticate users via OpenStack
   Identity Service (Keystone).